Optical scanner with segmented collection mirror

ABSTRACT

A multiple working range scanner includes a collection mirror which is segmented, with each segment having differing optical properties, such as focal length, optical axis, and so on. Differing segments or combinations of segments deal with reflected light received at differing working ranges, and direct it to a photodetector. In another embodiment, beam shaping may be applied to an astigmatic laser beam, for example by means of a part-concave mirror, to create an x waist in the beam which is further from the scanner than the y waist. This provides enhanced performance when the scanner is used on a bar code symbol which is not accurately aligned. In order to provide improved optical alignment within a bar code scanner, the collection mirror may be adjustable both in the x direction and in the y direction.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of Ser. No. 08/912,147, filedAug. 15, 1997, now issued U.S. Pat. No. 5,859,417, which is acontinuation of application Ser. No. 08/405,585, filed Mar. 17, 1995,now abandoned, which is a continuation-in-part of application Ser. No.08/268,982, filed Jun. 30, 1994, now issued U.S. Pat. No. 5,742,038,which is a continuation-in-part of application Ser. No. 08/314,519,filed Sep. 28, 1994, now issued U.S. Pat. No. 5,506,392, which is adivisional of application Ser. No. 08/109,021, filed Aug. 19, 1993, nowissued U.S. Pat. No. 5,352,922, which is a divisional of applicationSer. No. 07/735,573, filed Jul. 25, 1991, now issued U.S. Pat. No.5,278,397.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to optical scanners, and in particularin some embodiments to scanners having dual or multiple working ranges.

Most optical scanners such as bar code scanners are adapted for use at aparticular distance, or a range of distances, from an indicia to bescanned. If the user holds the scanner too close to the indicia, or toofar away, the indicia and/or the flying spot beam will not be in focus,and decoding will not be possible.

Such scanners may not be particularly convenient in environments where aseries of indicia to be read are presented to the scanner at variousdistances, and where it is difficult or impossible for the user to alterthe distance between the scanner and the indicia. To deal with suchsituations, attempts have been made to expand the acceptable workingrange of conventional scanners, to give the user as much leeway aspossible, and also to provide multi-distance scanners which can operate,for example, at a first working range or at a second working rangeaccording to the user's preference or requirements. One possibility isfor the provision of a two-position switch on the scanner, with thescanner operating at a first working distance in a first position of theswitch and at a second working distance in a second position. Adisadvantage of such scanners is that they require additional movingparts to provide for operation at the two separate working ranges. Suchsystems are also not “automatic” in the sense that the user has manuallyto select the correct working range, according to the distance of thecurrent indicia to be read; if the incorrect working range is chosen, adecode will not result.

One of the difficulties that bar code reader designers face whenattempting to produce increased working ranges is that the greater theworking range, and the greater the range of possible indicia that mightbe read, the lower tends to be the resultant signal to noise ratio inlight that is reflected from the indicia. One approach for dealing withthis involves the provision of non-conventional optics, in which theoptics associated with either the laser or with the photodetector havetwo distinct focal points. An example of this is shown in U.S. Pat. No.5,332,892, which is commonly assigned with the present application. Inthe device shown in that document, the two focal points are associatedwith corresponding circuitry to provide two separate channels of dataderived from the scanned bar code. The two channels have differingresolutions. As the working angle and density vary, at least one of theresolutions is likely to be appropriate for sensing all or most of thebar coded data, regardless of the distance of the bar code with respectto the scanner and/or the size or density of the code. The scanningbeams of bar code readers are typically derived from laser diodes. Suchdiodes are robust and relatively inexpensive, but they do suffer fromthe disadvantage that the beam emerging from a laser diode isastigmatic. The astigmatic laser diode can be characterised as havingtwo apparent light sources spaced apart from each other along theoptical path. One of the light sources lies in a horizontal plane,appears to be coming from inside the laser diode chip, and has a lowangular divergence. The other apparent light source lies in a verticalplane, appears to be coming from a facet of the chip, and has a highangular divergence. The two apparent light sources, which are spacedapart from each other by typically about 20 micrometers, form two beamwaists in different planes and in different directions, as measuredrelative to the planar junction of the chip.

The resultant relatively complex beam profile may need selective shapingbefore it can efficiently be used in an optical scanner. Some methods ofproviding such beam shaping are described in our co-pending U.S. patentapplication Ser. No. 08/268,982, filed Jun. 30, 1994, now U.S. Pat. No.5,742,038, the teachings of which are incorporated herein by reference.

A simpler option is simply to provide separate long and short rangevisible laser diodes, as is suggested in our earlier patent U.S. Pat.No. 5,420,411.

Yet a further option is to provide a multi-focus lens for the outgoinglaser beam, thereby providing that the outgoing laser beam may befocused on an object in a first predetermined working range andsimultaneously on a second object in a second predetermined workingrange.

Where a scanner has several different working ranges, a furtherdifficulty arises in that reflected light from a bar code at the farworking range will tend to be much weaker than light reflected from abar code in the near working range. This makes automatic gain control ofthe signal difficult. One approach to this problem is shown in U.S. Pat.No. 5,591,954, to Spencer. Spencer discloses a retro-reflectivearrangement in which common segmented mirrors are used both for scanningand for the collection of reflected light. Different segments are coateddifferently, in an effort to equalise the returned light intensity.

A further common difficulty with bar code scanners, particularly withscanners in which the y dimension of the scanning beam is greater thanthe x dimension, is that the y dimension can be too tall close to thescanner, so reducing the ability of the scanner to read high-densitysymbols when the symbol is not accurately aligned. In particular,difficulties can occur when the longer axis of the beam cross-section isnot parallel with the bars and spaces in the symbol to be read. Thisproblem can be reduced by decreasing the vertical dimension of the laseraperture, but this can sometimes be unacceptable since it results in theloss of laser power.

It is well known that it is advantageous to focus the laser beam, in abar code scanner, so that it is taller than it is wide. The tall spotreduces speckle and paper noise by increasing the overall spot area, andhelps to filter out small printing defects. The width of the spot, onthe other hand, is determined by the performance requirements of thescanner. The width is normally chosen so that it is small enough toresolve the smallest elements in a bar code symbol which the scanner isrequired to read.

Various means of creating elongate laser spots have been used. One isshown in U.S. Pat. No. 5,440,111 to Eastman. This system orients thelaser so that the laser's astigmatism causes the spot to be narrower inthe direction of spot motion (the x direction) than it is in thedirection perpendicular to the direction of motion (the y direction).The amount of elipticity of the laser spot, in this system, is dependenton the amount of astigmatism that the laser has, and by themagnification of the focusing system.

SUMMARY OF THE INVENTION Objects of the Invention

It is an object of the present invention at least to alleviate theproblems of the prior art.

It is a further object to enhance the performance of scanners havingmultiple working ranges.

It is yet a further object to provide a scanner with improved readingcharacteristics when the symbol to be read is presented in anorientation which is not ideal.

It is a further object to reduce the costs of manufacturing a scannerhaving parts in accurate optical alignment.

FEATURES OF THE PRESENT INVENTION

According to a first aspect of the present invention there is providedan optical scanner for reading indicia comprising:

(a) a beam generator and scanner for producing a scanning light beam anddirecting said light beam toward an indicia to be read;

(b) a light detector; and

(c) a collection mirror for receiving reflected light, the collectionmirror having at least first and second segments of differing opticalproperties whereby said first segment reflects toward the detector lightreceived from an indicia at a first working range from the scanner andsaid second segment reflects toward the detector light received from anindicia at a second, different, working range.

Such an arrangement improves scanner performance via the collectionmirror which is composed of two or more separate segments. Each segmentpreferably has a different optical surface, such as a difference infocal length, surface orientation, aberration or surface definition (forexample, paraboloid rather than spherical). At least one segment directslight back to the photodetector from an indicia which is at a firstworking distance. At least another segment directs light back to thephotodetector from an indicia which is at a second working distance. Thesegments may operate independently, so that one segment operates only atthe first working distance and the other operates only at the secondworking distance. Alternatively, one segment may operate only at thefirst working distance, while the second returns light from indicia bothat the first and the second working distances. Alternative arrangementsmay be envisaged in which there are more than two segments.

The segments are preferably contiguous with one another, and may beintegrally molded. In one embodiment, the segments are adjacent to oneanother, and in another one segment surrounds the second in a coaxialfashion.

Maximum signal strength may be achieved, and automatic gain controlsimplified, where both mirror segments collect light from an indicia ata far working distance, but only one of them collects light from anindicia at a near working distance.

In laser bar code scanners, the size of field of view is critical to thescanner performance, especially under strong ambient light conditions.Reducing the field of view angle will typically improve performance, butoptical alignment during manufacture becomes more difficult and laborintensive.

According to the present invention, this difficulty is solved byproviding the collection mirror with a field of view angle adjustment,allowing accurate alignment of the mirror with the other opticalcomponents within the scanner. Preferably, the mirror may be adjusted inangle both in the x and y axis directions. Ideally, x and y axistranslation of the mirror is also possible.

An adjustable mirror of this type may be used in conjunction with theoptical scanner previously described, or may be used independently.

A collection mirror of this type having both x axis and y axis angularadjustment can align the field of view angle of the receiving optics tothe laser beam axis with very high accuracy. Assuming that the x and yangular adjustments are independent of each other, the total systemfield of view angle may typically be controlled to within about plus orminus 2°.

According to a further aspect of the present invention there is providedan optical scanner for reading indicia by effecting a scanning motion ofa light beam in an x-axis direction across an indicia to be read, saidscanner comprising:

(a) a laser for producing a light beam of non-circularly-symmetriccross-section, having an x-axis and a y-axis, beam divergence in the xaxis being greater than beam divergence in the y axis;

(b) negative beam-shaping optics in the beam for adjusting the y axisdivergence independently of the x axis divergence.

Such an arrangement improves scanner performance, particularly in thereading of bar code symbols which are not accurately aligned along thescanning (x) axis. In this invention the laser has been rotated so thatits wider divergence angle is horizontal (in the x axis direction), thebeam height (y) at the laser aperture is quite small. The vertical (y)dimension of the aperture can therefore be reduced without sacrificinglaser power.

It is also not necessary, in contrast with the prior art such as theabove-mentioned Eastman U.S. Pat. No. 5,440,111, to use highermagnification to increase the separation between the x and y waists inthe beam. In the present invention, the spacing between the waists iscontrolled not by magnification, but by the negative optical element inthe laser path. Adequate waist separation is possible even with lowermagnification systems.

The negative optical element in the laser path is preferably cylindricalor part-cylindrical, thereby allowing independent control of the y-axisdimension of the beam cross-section. Preferably the optical elementcomprises a part-cylindrical mirror having a longitudinal axis which ishorizontal (in the x-axis direction). In the preferred embodiment, thecylindrical element is molded into a plastic fold mirror. This is astandard element in most scanning systems in any event, so the inventionadds very little extra cost. There is also no additional loss of opticaloutput power as would occur if an additional lens were to be added tothe system.

The invention is particularly although not exclusively useful inconnection with index guided lasers, in which astigmatism is typicallyrather lower than is the case with gain guided lasers. Previously, gainguided lasers have been preferred in this type of application, for thevery reason that their astigmatism is typically higher which results ingreater separation between the x and y waists of the focused beam. Thisis important because if the waists were close together, the spot areawould be very small near the waist resulting in a noisy signal in thisarea. Separating the waists helps to avoid this.

The present invention opens up this field to the use of index guidedlasers. It further provides simplification, in that adjustment betweenthe x and y waists may now be achieved without change in magnification.

BRIEF DESCRIPTION OF THE DRAWINGS:

The invention may be carried into practice in a number of ways andseveral specific embodiments will now be described, by way of example,with reference to the accompanying drawings, in which:

FIG. 1 illustrates a prior art scanner;

FIGS. 2a and 2 b represent alternative embodiments of the invention inwhich the collection mirrors are segmented,

FIGS. 3a and 3 b show the collection mirrors of FIGS. 2a and 2 brespectively in more detail;

FIG. 4 illustrates an adjustment mechanism for a collection mirror;

FIG. 5 identifies the x and y axes to be used throughout thisspecification and claims;

FIGS. 6 and 7 show how the beam profile varies in one previously knownscanner; and

FIGS. 8 and 9 show how the beam profile varies in a further embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates schematically one specific variety of optical or barcode scanner.

A laser diode assembly 10 including a laser diode 12 and beam-shapingoptics 14 creates a shaped laser beam which impinges upon an oscillatingmirror 16, mounted for oscillatory movement about an axis 18, to createan outgoing scanning beam 20. The outgoing scanning beam leaves thescanner housing 22 via a window 24, and is directed toward a bar codesymbol or other indicia 26 to be read. The bar code symbol is printed orotherwise attached to a substrate 28. The scanning beam 20 creates a“flying spot” P which moves across the substrate and consequently acrossthe bar code to be read.

Light 30 reflected from the bar code returns via the window 24 where itis collected by a collection mirror 32 and directed toward aphotodetector 34. The photodetector provides an output electrical signal(not shown) from which the relative width of the bars and spaces in thecode may be determined. From this information, the bar code symbol maybe decoded to recover the information that it contains.

One disadvantage of this type of bar code scanner is that it has alimited working range. If the bar codes symbol is positioned too closeto the scanner housing, or too far away, the signal to noise ratiotypically becomes too high and the bar code symbol cannot easily bedecoded.

FIG. 2a illustrates an improvement, embodying the present invention, tothe scanner of FIG. 1. In the arrangement of FIG. 2a, the collectionmirror 32 is replaced by a two-section collection mirror 32′, having afirst section 29 a and a second section 29 b. FIG. 3a shows thecollection mirror 32′ from the front.

The mirror sections 29 a, 29 b have differing profiles such that anobject P_(f) placed at a far working distance is imaged by the section29 a, while an object P_(n) placed at a near working distance is imagedby the section 29 b. More generally, the section 29 a is responsible forobjects within a far working range, whereas the section 29 b isresponsible for objects within a near working range.

The mirror segments 29 a, 29 b have differing optical surfaces. Theywill typically have differing focal lengths, but they may also oralternatively have differing surface orientations, aberrations, orsurface definitions (paraboloid instead of spheroidal for example).

Another embodiment of the invention is shown in FIG. 2b. Here, thecollection mirror has a coaxial configuration, best seen in FIG. 3b, andincludes an inner circular segment 3 la and an outer annular segment 31b. In this embodiment, both of the mirror segments collect lightreceived from a far object P_(f), and direct it towards thephotodetector 34. Since the two segments once again have differingoptical characteristics, for example differing focal lengths, not all ofthe light received from P_(f) will focus at exactly the same point, but,as shown in the drawing, all of it can be received by the photodetectorby virtue of the photodetector's size. Some of the light received may befocused on one point of the photodetector, and some on another, but inboth cases the photodetector receives a signal. Light received from anear object P_(n) is reflected towards the photodetector solely by theinner segment 31 a. Such an arrangement provides for maximum signal whenthe scanner is operated at its far working range. The increase in signalat the far range due to the segment 31 b tends to balance out the lossof light consequent upon the inverse square law, thereby allowing easierautomatic gain control of the signal at both the near and the farworking ranges.

The segments 31 a, 31 b may differ by means of focal length, surfaceorientation, aberrations or surface definition (paraboloid for example,rather than spherical).

It will be understood that alternative topologies are possible, inaddition to the arrangements described. Additional segments could beprovided, for example, to allow for multiple working ranges. The mirrorshape may be rectangular or square, rather than circular. The segmentsneed not be contiguous. Both segments in FIG. 3a could return light froman object in the far working range, with only one of them returninglight from the near working range. Each of the segments illustrated inFIG. 3b may return light from only one of the near working range or thefar working range, but not both. The same concepts may be applied toretro-reflective scanners, in which the collection mirror is oscillatedwith a portion of the mirror serving to reflect the outgoing laser beam,as well as collecting the incoming reflections. Other configurationswill occur to the skilled man.

In laser bar code scanners, the size of the field of view is critical toscanner performance, especially when the scanner is to be used understrong ambient light conditions. Reducing the field of view angleimproves performance but makes optical alignments of the variouscomponents much more difficult and labor intensive at the manufacturingstage. The problem can be alleviated by arranging for the collectionmirror to be adjustable in position and/or angle.

One example of an adjustable collection mirror 32 is given in FIG. 4.The mirror 32 has a rear surface 40, opposite its reflecting surface 42,to which is attached a mirror mount 44. The mirror is adjustable inangle, as shown in the arrows 58, by rotation about the pivot axis 54.Translation of the mirror in the directions shown by the double-headedarrow 56 is also provided for. To that end, the mount 44 is secured to asliding mount 46 which can slide along a fixed bar 50. A locking nut isprovided at 52.

A similar arrangement (not shown) may allow the mirror to rotate and tobe translated in a perpendicular direction from that shown in FIG. 4.Since both positional and angular adjustments can be made independentlyof each other, the total system field of view angle can be controlledvery accurately, typically to within about plus or minus 2°.

It is well known that it is advantageous to focus the laser beam, in abar code scanner, so that it is taller than it is wide. The tall spotreduces speckle and paper noise by increasing the overall spot area, andhelps to filter out small printing defects. The width of the spot, onthe other hand, is determined by the performance requirements of thescanner. The width is typically chosen so that it is small enough toresolve the smallest elements in a bar code symbol which the scanner isrequired to read. Before discussing a further embodiment having animproved beam profile, reference should first be made to FIG. 5 whichillustrates the terminology that will be used.

FIG. 5 shows a front view of a typical bar code symbol 60 on a substrate62. The x and y axes, to be referred to below, are defined as shown,with the x axis extending longitudinally of the bar code, and the y axisgenerally parallel to the lines. More generally, the x axis is definedas the direction parallel to which the bar code symbol is scanned, forexample parallel to the direction of motion of a “flying spot”. When atwo-dimensional bar code or other indicia is to be captured, scanningmay be carried out by means of a raster pattern over the indiciacomprising a plurality of parallel scan lines in the x direction, thelines being spaced apart from one another in the y direction.

Similar x and y axes may be applied to the outgoing laser beam bothbefore and after it has impinged upon the oscillating mirror or otherscanning element. Of course, since the outgoing laser beam may bereflected and bent several times before it leaves the scanner, the xaxis, applied to the cross-section of the beam, will not necessarily becoincident in direction with the x axis shown in FIG. 5. Nevertheless,the x axis when applied to the beam cross-section can be defined, at anypoint, as that axis which will, after all appropriate reflections havebeen completed, map onto the x axis shown in FIG. 5 when the beamimpinges upon the indicia to be read. A similar rule applies to the yaxis.

With those definitions in mind, we can now turn to FIGS. 6 and 7 whichillustrate a prior art scanner which incorporates beam shaping. Thescanner includes a laser diode assembly 100 having a laser diode 102 andbeam shaping optics 104. The laser diode 102 is a gain guided laserhaving high astigmatism so that the beam fans out much more in onedirection than in the other. In the device shown, the laser is alignedso that the beam fans out in the y direction. The beam shaping optics104 includes a cylindrical element to shape the beam. The shaped beam106 is reflected from a planar fold mirror 108, and the resultantreflected beam 110 is then further reflected from a scanning mirror 112to produce a scanning outgoing beam 114. This leaves the scanner housing(not shown) via a window 116.

FIG. 7 schematically illustrates the beam profile on the far side of thewindow 116. The upper traces represent the beam width in the xdirection, at various distances from the window, and the lower tracesthe y width. As may be seen, the beam has an x waist W_(x) at arelatively close distance d_(n), and has a y waist W_(y) at a furtherdistance d_(f).

Such an arrangement has one drawback, in that the y dimension of thebeam can be too tall close to the scanner, reducing the ability of thescanner to read high density symbols when the scan line (which isnormally in the x direction) is not exactly perpendicular to the barsand spaces in the symbol. This problem can be reduced by decreasing thevertical dimension of the laser aperture, within the optical assembly104, but this also reduces the laser power. Sometimes, the loss of laserpower may be unacceptable.

A new approach is shown in the embodiment of FIG. 8. Here, a laser diodeassembly 100′ includes a laser diode 102′ and an optical assembly 104′.The laser 102′ is astigmatic, and may be either a gain guided laser oran index guided laser. The laser is positioned so that the unmodifiedbeam tends to fan out in the x direction (in other words, the laser isrotated through 90° from that shown in FIG. 6).

In this embodiment, the laser optics 104′ need not incorporate anycylindrical optical elements. Instead, a naturally flattened beam 106′impinges upon a stationary fold mirror 108′, from which it is reflectedat 110′ toward the scanning mirror 112′. The fold mirror 108′ ispart-cylindrical and acts as a negative (concave) cylindrical opticalelement in the laser path. The cylinder's axis is in the x direction,parallel to the wide divergence angle of the laser.

Such an arrangement modifies the outgoing scanning laser beam 114′ sothat, on the far side of the scanner window 116′, it is shaped as shownin FIG. 9. The negative optical element 108′ moves the y waist W′_(y)closer to the scanner, separating it from the x waist W′_(x) which isfurther out. Such an arrangement largely eliminates the problem oflimited roll tolerance that results from a laser spot that is too tallclose to the scanner. When the laser is rotated so that its widerdivergence lies along the x axis, the beam height at the laser apertureis quite short. The vertical dimension (the y axis) of the aperture cantherefore be reduced without sacrificing laser power.

In alternative arrangements, the fold mirror 108′ could be replaced withany other appropriate means for introducing a negative non-rotationallysymmetric optical element into the laser's path. For example, thescanning mirror 112′ could be part-concave; alternatively, a negativecylindrical lens or other optical element could form part of the opticalassembly 104′. A similar effect could be achieved by means of one ormore holographic optical elements.

It will be appreciated of course that any two or more of the featuresdescribed in the various embodiments may be combined, as desired, withina single scanner. For example, the adjustable collection mirrorillustrated in FIG. 4 could be used in conjunction with the arrangementsof FIG. 2, or even with the otherwise lone arrangement of FIG. 1. All ofthe concepts are applicable for use in “staring type” scanners, in whichthe collection mirror is stationary, and in “retro-reflective” scanners,in which the collection mirror itself oscillates and acts not only tocollect the received light but also acts as the scanning element.

While the invention has been illustrated as described with reference toa number of particular embodiments, it is not intended to be limited toany of the details shown, since various modifications and structuralchanges may be made without departing in any way from the spirit of thepresent invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.Accordingly, such adaptations should be and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed is:
 1. An optical scanner for reading indiciacomprising: (a) a beam generator and scanner for producing a scanninglight beam and directing said light beam toward an indicia to be read;(b) a light detector; and (c) a collection mirror for receivingreflected light, the collection mirror having at least first and secondnonplanar segments of differing optical properties, each of the firstand second segments having an optical curvature and being sized andpositioned to serve primarily as a collection mirror for collectinglight received from an indicia and directing it toward the lightdetector, and not primarily as a scanning mirror for directing the lightbeam toward the indicia, whereby said first segment reflects toward thedetector light received from an indicia at a first working range fromthe scanner and said second segment reflects toward the detector lightreceived from an indicia at a second, different, working range.
 2. Anoptical scanner according to claim 1 wherein said first segment has afirst focal length and said second segment has a second, different,focal length.
 3. An optical scanner according to claim 1 wherein saidfirst segment has a first optical axis and said second segment has asecond, different, optical axis.
 4. An optical scanner according toclaim 1 wherein said first segment has a first optical curvature andsaid second segment has a second, different, optical curvature.
 5. Anoptical scanner according to claim 1 wherein said first and secondsegments are contiguous.
 6. An optical scanner according to claim 1where in said first and second segments are adjacent to one another, andshare a common boundary.
 7. An optical scanner according to claim 1wherein said first segment is circular and wherein said second segmentis annular and surrounds said first segment.
 8. An optical scanneraccording to claim 1 wherein said first and second segments areintegrally molded.
 9. An optical scanner according to claim 1 whereinsaid first segment reflects toward said detector light received from anindicia whether at the first working range or the second working range;and the second segment reflects toward said detector light received froman indicia only when it is at the first working range.
 10. An opticalscanner according to claim 1 including an adjustable mount for alteringthe alignment of the collection mirror.
 11. An optical scanner accordingto claim 10 wherein the adjustable mount is adjustable in angle in bothx and y directions.
 12. An optical scanner according to claim 10 whereinthe adjustable mount is adjustable in position in both x and ydirections.